Refrigerating apparatus



Dec. 17, 1929. s. M. SCHWELLER REFRIGERATING APPARATUS .Filed Oct. 3, 1923 Patented a... 17, 1929 UNITED STATES PATE OFFICE.

I SYLVESTER M. SCHWELLER, OI DAYTON, OHIO; ASSIGNOB, BY MESNE ASSIGNMENTS,

I TO FRIGIDAIRE CORPORATION, A CORPORATION OF DELAWABE BnrRIeEnArmo APPARATUS Application filed October 3, 1923. Serial No. 866,246.

This invention relates to refrigerating apparatus of thecompressor-condenser-expander circuit type, and more particularly to means for regulating and controlling the supply of liquid refrigerant supplied from the high pressure side of a refrigerating machine tothe expander or boiler which con'sti-.

tute the cooling unit.

The principal object of the invention is to safeguard the apparatus in the event that the automatic means for controlling the supply of liquid refrigerant to the cooling unit fails to function.

The invention consists in means responsive to pressure to open a passage from the high pressure or liquid conduit to the expanding unit, and in means responsive to valuations of pressure cooperating with a means responding to variations of temperature to regulate the escape of fluid to said expanding unit. It further consists in the. combinations and details of structure specifically described hereinafter, illustrated in the accompanying drawings and .defined in the appended claims.

In the accompanying drawings, Fig. 1 is a diagram of a refrigerating apparatusof the compressor-condenser-expander circuit type, showing the preferred location of the device that is the subject of this application with respect to the entire apparatus; Fig. 2 is a vertical section of the regulating device to which the invention particularly relates, and Fig. 3 is a cross sectionon line 33 of Fig. 2.

In the diagram (Fig. 1) 10 indicates a compressor as a whole which is driven by a motor 11; 12 an expansion element or boiler comprising an evaporating tank 12 and a coil 12. The high pressure or liquid line comprises the piping 13 from the high pressure side of the compressor to the condenser,

the condenser 14, piping 15mm the condenser to the regulating device, and the regulating device 16. The low pressure line comprises'the piping 17 from the regulating device to the expander or boiler 12, said expander. and-the return pipe or vapor line 18 from the expander 12 to the low pressure side of the compressor 10. The expander'element and the device 16 are intended to be housed in a cooling compartment of a refri construction, but will be described in full in order to make clear the relation of the new elements to that which was previously known.

The regulating device16 comprises a body having a chambered portion 19 which may be conveniently of circular cross section and from which a reduced tubular portion 20 extends upward from one end in an axial direction and a reduced tubular portion 21 extends downward from the other end coaxially with the chambered portion 19 and extension 20. The extension 21 is separably connected to the portion 19 as shown. The high pressure or liquid line pipe 15 is tapped into the side of chambered portion 19 near the upper end of the chamber and the low pressure p1 e section 17 is connected to lower end of the tubular extension 21 within which is a means for opening and closing the passage therethrough comprising a valve and valve seat adapted automatically to regulate the passage of refri erant, as will be presently explained. Refrigerant enters the chamber within the chambered portion 19 through pipe 15, and leaves it through the lower tubular extension 21 and pipe 17.

The valve seat referred to as within the tubular extension 21 is formed in a, perforated valve member 22 and cooperates with a valve 23. The valve 23 may move v toward or from the seat member 22 in response to .variations of pressure within the chamber,

and beyon the flan e, on the' upper side,

is a piston-like mem er 28, having on its upper extremity a spring-centerin stud 29. Threaded at 30 in the lower end o the bore 1 that traverses the u per extension 20 is a tubular member 31 en arged between its ends into a wide flange 32. That portion of the member '31 that reaches below flange 32 contains a bore 33 that fits over and telescopes with the piston-like ortion 28 described as connected to the va ve stem 24 and fian e 27. Small holes 33 may penetrate to t e bore from the exterior. A smaller bore 34 traverses the upper part of member 31 from the bore j 33 completel through said part.

A metallic, transverse y corrugated, lon itudinall collapsible and expansible tubu arf bodyor ellows like member 36 is hermetically sealed at opposite ends to the flanges 27 and 32, respectively. At its upper end member 31 is formed exteriorly at'35 so that it may be engaged by'a socket wrench or other suitable tool and rotated in either direction. A coiled compression sprin 37 is disposed within the bore 33 between 1ts up- 'per end and the upper end of the iston like member 28 whereon it is centered y the stud 29. I It will thus be evident'that expansion of I as the bellows tends to move the valve ina direction to reduce or cut ofi'the flow of fluid into pipe 17 and contraction of said bellows tends'to move the valve upward away from its seat to permit the flow of fluid into pipe 40 17; also that by rotating the member 31 in one direction it will be screwed downward to increase the pressure of spring 37, and by rotating it in the op osite direction it will be screwed upward t ereby decreasing ts pressure.

Leakage of fluidfrom or into the chamber within body 19 is prevented by an ad-' justable stufling box 38 disposed above a shoulder 39 formed by an enlargement of the assage in extension 20. The u per end "of t e bore or duct 34 in art 31 is closed by a'headed screw plug 40 eneath the head of which there may be a packing gasket 41.

The upper end of the passa through upper extension 20 ma be close by-a screw cap 42 that may be tted in said extension fluid tight by the aid of a packing gasket 43.

When the space within the bellows 36 is charged with a suitable uantity of the same 63 kind'of fluid (such as su phur dioxide) that is used in thecirculatory system as a refrigerant, the bellows with the flanges to which it is sealed constitute a thermostatic device that will move the valve 23 under the influ- 65 ence of changes of temperature Within the of s ring range it is constructed andadjusted to re# spond to. The fluid may be charged into the ermostatic chamber through the upper end of bore 34 in member 31 after removal of cap 42 and screw cally sealed-t erein by replacing of screw 11 lbos eness of fit between the iston like body 28 and the inside surfaceof th in member 31 to permit the thermostatic fluid to pass around the piston to the bellows chamber although the holes 33 are intended as assages for this fluid.

he thermostatic device, by itself, is not herein claimed, the invention which is the subject of this application relating particularly to' the combination with the thermostatic device of a pressure sensitivemeans, and in said pressure sensitive means itself, ada ted to operate to open a passage from the igh pressureto the low pressure side under abnormal conditions, that is in case the'valve stem should stick in the ide or lug 40, and may be hermeti- 40. There is intended to be suflicient' e large bore 33 the pressures within and without the bellows should become e ualized through leakage of fluid through the portion 31 lnto the bore 33, or if for any other reason the valve 23 should fail to open according to its ordained law of operation.

The lower end of lower extension 21 of body 19 is counterbored forming thereby an internal shoulder 44, and is reamed to a tapered entrance provided with internal threads to engage the coupling used to con nect ipe 17 thereto. The member 22 previous y referred to, which is provided centrally with a fluid port 45 adapted to be llows or around the upper opened or closed by valve 23, is disposed shoulder 44, by valve 23. Member 22moves' 1 away from shoulder 44 when the pressure built up by the fluid within the chambered body 19 is suflicient toovercome the pressure Smce the fluid within the bellows36 is the same as that-outside of it and is subject to the same laws as res ects heat and pressure, it will be apparent t at the bellows will remain stationary when the ressure is substantially the same on the insi e and the outside of the bellows. The spring 37 maintains the valve 23 on its seat member 22 when the pressure in the chamber portion 19 issubstantially the same as the pressure within bellows 36. When the compressor operates, the refrigerant fluid will be compressed, cooled by the condenser 14 and liquefied.- The liquid re fri erant adjacent valve 16 will be somewhat col er than the refrigerant in pipe13 and that in the first part of condenser 14 due to the cooling eifect of the condenser. The compressor, however, tends to raise the pressure of the fluid in the pi e 13 and the first part of the condenser to t e condensin pressure. The pressure of the fluid within be ows 36 is responsive to the temperature of the liquid refrigerant within chamber portion 19. When the differential between the pressure on the exterior of the bellows 36 and the pressure in the bellows exceeds that of spring 37 due to the operation of the compressor, the v bellows will collapse to raise valve 23 from its seat.

chamber into the pipe 17 and thence to the expander or evaporating element 12.. Afterthe temperature of the evaporating element or its surroundings have been cooled to the desired degree, the motor 11 ma I be stopped 25 by any known means or in any nown manner. The compressor then stops and during this condition of quiescence no refrigerant liquid will 'enter the chamber around the thermostat. The temperatures and pressures within the bellows and surrounding chamber will therefore equalize. As a result the valve 23 will again close the port 22. During the. operation of the motor and compressor, the bellows 36 is collapsed periodically to' ermit accumulation and release of liquid re rigerant without stoppage of the motor and com pressor.

Should the valve stem stick, by reason of corrosion of the stem 24 so that the bellows cannot liftthe valve from its seat, or should a leak develop anywhere so that fluid passes between the interior and exterior of the bellows renderinga diflerential impossible and the valve remains in its closed position while the chamber is being charged with liquid by the compressor, valve seat member 22 will be pressed awa from shoulder 44 and let the liquid pass into pipe 17 when the predetermined pressure suflicient to overcome the elas- 50 tic pressure of the spring 46 has been built up by the compressor. Fluid may passaround the member 22 even though the needle valve 23 should followits movement away from the seat. Under these abnormal condi- 2. A refrigerating system comprising combination, a fluid circuit having high and low pressure portions; means for circulatln'g refrigerating fluid within said circuit; and a.

pressure reducing valve including a movable valve member responsive to normal conditions of the fluid in said circuit for controlling the flow of fluid from the high pressure portion to the low pressure portion, and a movable valve seat member associated with said first valve memberand res onsiue to an abnormal condition of said uid for interconnecting the low pressure portion with the high pressure portion.

' 3. A refrigerating system comprising in combination, a fluid circuit having high and 3 low pressure portlons; meansfor circulating v 95 means responsive to normal conditions of the refrigerating'fluid within saidcircuit; and

with ,the high presfluid in said circuit for controlling ,the flowf thereof from the high pressure portion to the low pressure portion, said means including a second means responsive to abnormal pressure of said fluid ,in said high pressure portion for interconnecting the low pressure portion with thehigh pressure portlon.

In testimony'whereof- I hereto aflix my signature.

* SYLVESTER M. SCHWELLER.

tions the refrigerant would circulate harm- I 

